#!/bin/bash
#
# Developed by Fred Weinhaus 12/11/2012 .......... revised 10/9/2014
#
# ------------------------------------------------------------------------------
# 
# Licensing:
# 
# Copyright © Fred Weinhaus
# 
# My scripts are available free of charge for non-commercial use, ONLY.
# 
# For use of my scripts in commercial (for-profit) environments or 
# non-free applications, please contact me (Fred Weinhaus) for 
# licensing arrangements. My email address is fmw at alink dot net.
# 
# If you: 1) redistribute, 2) incorporate any of these scripts into other 
# free applications or 3) reprogram them in another scripting language, 
# then you must contact me for permission, especially if the result might 
# be used in a commercial or for-profit environment.
# 
# My scripts are also subject, in a subordinate manner, to the ImageMagick 
# license, which can be found at: http://www.imagemagick.org/script/license.php
# 
# ------------------------------------------------------------------------------
# 
####
#
# USAGE: accentedges [-w width] [-s strength] [-p polarity] [-b blur] 
# [-c cmethod] infile outfile
#
# USAGE: accentedges [-help]
#
# OPTIONS:
#
# -w     width        width of edges; integer>0; default=1
# -s     strength     strenght of edges; integer>=0; default=20
# -p     polarity     polarity of edges; choices are: white or black; 
#                     default=black
# -b     blur         blurring (smoothing) of edges; float>=0; default=0.5
# -c     cmethod      compose method for blending edges with image; choices 
#                     are: over or overlay; default=over
#
###
#
# NAME: ACCENTEDGES 
# 
# PURPOSE: To apply accented edges to an image.
# 
# DESCRIPTION: ACCENTEDGES applies accented edges to an image. The edges may 
# be either black or white. The compose method may be either over or overlay 
# for slightly different effects. This script attempts to duplicate some of the 
# features of Photoshop's Accented Edges.
# 
# OPTIONS: 
# 
# -w width ... WIDTH of the edges. Values are integers>0. The default=1.
# 
# -s strength ... STRENGTH of the edges. Values are integers>=0. The default=20.
# 
# -p polarity ... POLARITY of the edges. The choices are: white or black. The  
# default=black.
# 
# -b blur ... BLUR is the blurring (smoothing) of the edges. Values are 
# floats>=0. The default=0.5.
# 
# -c cmethod ... CMETHOD is the compose method for blending the edges with 
# the image. The choices are: over or overlay. The default=over.
#
# REQUIREMENTS: IM 6.5.9.3 is required due to the use of -morphology edgeout.
#  
# CAVEAT: No guarantee that this script will work on all platforms, 
# nor that trapping of inconsistent parameters is complete and 
# foolproof. Use At Your Own Risk. 
# 
######
#

# set default values
width=1				# edge width
strength=20			# edge strength
polarity="black" 	# edge polarity
blur=0.5			# edge blur	
cmethod="over"		# compose method: over or overlay

# set directory for temporary files
dir="."    # suggestions are dir="." or dir="/tmp"

# set up functions to report Usage and Usage with Description
PROGNAME=`type $0 | awk '{print $3}'`  # search for executable on path
PROGDIR=`dirname $PROGNAME`            # extract directory of program
PROGNAME=`basename $PROGNAME`          # base name of program
usage1() 
	{
	echo >&2 ""
	echo >&2 "$PROGNAME:" "$@"
	sed >&2 -e '1,/^####/d;  /^###/g;  /^#/!q;  s/^#//;  s/^ //;  4,$p' "$PROGDIR/$PROGNAME"
	}
usage2() 
	{
	echo >&2 ""
	echo >&2 "$PROGNAME:" "$@"
	sed >&2 -e '1,/^####/d;  /^######/g;  /^#/!q;  s/^#*//;  s/^ //;  4,$p' "$PROGDIR/$PROGNAME"
	}


# function to report error messages
errMsg()
	{
	echo ""
	echo $1
	echo ""
	usage1
	exit 1
	}


# function to test for minus at start of value of second part of option 1 or 2
checkMinus()
	{
	test=`echo "$1" | grep -c '^-.*$'`   # returns 1 if match; 0 otherwise
    [ $test -eq 1 ] && errMsg "$errorMsg"
	}

# test for correct number of arguments and get values
if [ $# -eq 0 ]
	then
	# help information
   echo ""
   usage2
   exit 0
elif [ $# -gt 12 ]
	then
	errMsg "--- TOO MANY ARGUMENTS WERE PROVIDED ---"
else
	while [ $# -gt 0 ]
		do
			# get parameter values
			case "$1" in
		  -h|-help)    # help information
					   echo ""
					   usage2
					   exit 0
					   ;;
				-w)    # get width
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID WIDTH SPECIFICATION ---"
					   checkMinus "$1"
					   width=`expr "$1" : '\([0-9]*\)'`
					   [ "$width" = "" ] && errMsg "--- WIDTH=$width MUST BE A NON-NEGATIVE INTEGER ---"
					   test=`echo "$width < 1" | bc`
					   [ $test -eq 1 ] && errMsg "--- WIDTH=$percent MUST BE A POSITIVE INTEGER ---"
					   ;;
				-s)    # get strength
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID STRENGTH SPECIFICATION ---"
					   checkMinus "$1"
					   strength=`expr "$1" : '\([0-9]*\)'`
					   [ "$strength" = "" ] && errMsg "--- WIDTH=$strength MUST BE A NON-NEGATIVE INTEGER ---"
					   ;;
		 		-p)    # polarity
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID POLARITY SPECIFICATION ---"
					   checkMinus "$1"
					   # test gravity values
					   polarity="$1"
					   polarity=`echo "$1" | tr '[A-Z]' '[a-z]'`
					   case "$polarity" in 
					   		black) ;;
					   		white) ;;
					   		*) errMsg "--- POLARITY=$polarity IS AN INVALID VALUE ---" 
					   	esac
					   ;;
				-b)    # get blur
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID BLUR SPECIFICATION ---"
					   checkMinus "$1"
					   blur=`expr "$1" : '\([.0-9]*\)'`
					   [ "$blur" = "" ] && errMsg "--- BLUR=$blur MUST BE A NON-NEGATIVE FLOAT ---"
					   ;;
		 		-c)    # cmethod
					   shift  # to get the next parameter
					   # test if parameter starts with minus sign 
					   errorMsg="--- INVALID CMETHOD SPECIFICATION ---"
					   checkMinus "$1"
					   # test gravity values
					   cmethod="$1"
					   cmethod=`echo "$1" | tr '[A-Z]' '[a-z]'`
					   case "$cmethod" in 
					   		over) ;;
					   		overlay) ;;
					   		*) errMsg "--- CMETHOD=$cmethod IS AN INVALID VALUE ---" 
					   	esac
					   ;;
				 -)    # STDIN and end of arguments
					   break
					   ;;
				-*)    # any other - argument
					   errMsg "--- UNKNOWN OPTION ---"
					   ;;
		     	 *)    # end of arguments
					   break
					   ;;
			esac
			shift   # next option
	done
	#
	# get infile and outfile
	infile="$1"
	outfile="$2"
fi

# test that infile provided
[ "$infile" = "" ] && errMsg "NO INPUT FILE SPECIFIED"

# test that outfile provided
[ "$outfile" = "" ] && errMsg "NO OUTPUT FILE SPECIFIED"


# set up temp files
tmpA1="$dir/accentedges_A_$$.mpc"
tmpA2="$dir/accentedges_A_$$.cache"
trap "rm -f $tmpA1 $tmpA2;" 0
trap "rm -f $tmpA1 $tmpA2; exit 1" 1 2 3 15
trap "rm -f $tmpA1 $tmpA2; exit 1" ERR


# get im version
im_version=`convert -list configure | \
	sed '/^LIB_VERSION_NUMBER */!d; s//,/;  s/,/,0/g;  s/,0*\([0-9][0-9]\)/\1/g' | head -n 1`

# colorspace RGB and sRGB swapped between 6.7.5.5 and 6.7.6.7 
# though probably not resolved until the latter
# then -colorspace gray changed to linear between 6.7.6.7 and 6.7.8.2 
# then -separate converted to linear gray channels between 6.7.6.7 and 6.7.8.2,
# though probably not resolved until the latter
# so -colorspace HSL/HSB -separate and -colorspace gray became linear
# but we need to use -set colorspace RGB before using them at appropriate times
# so that results stay as in original script
# The following was determined from various version tests using accentedges.
# with IM 6.7.4.10, 6.7.6.10, 6.8.0.8
if [ "$im_version" -lt "06070607" -o "$im_version" -gt "06070707" ]; then
	setcspace="-set colorspace RGB"
else
	setcspace=""
fi
# no need for setcspace for grayscale or channels after 6.8.5.4
if [ "$im_version" -gt "06080504" ]; then
	setcspace=""
fi


# read input image
convert -quiet "$infile" $setcspace +repage $tmpA1 ||
	echo  "--- FILE $infile DOES NOT EXIST OR IS NOT AN ORDINARY FILE, NOT READABLE OR HAS ZERO SIZE  ---"


# divide strength by 10
strength=`convert xc: -format "%[fx:$strength/10]" info:`

# set up blur
if [ "$blur" = "0" ]; then
	blurring=""
else
	blurring="-blur 0x$blur"
fi

convert $tmpA1 \
	\( -clone 0 -fill $polarity -colorize 100 \) \
	\( -clone 0 $setcspace -colorspace gray \
		-morphology edgeout diamond:$width $blurring -evaluate multiply $strength \) \
	-compose $cmethod -composite "$outfile"


exit 0


